Collecting metrics via Prometheus

Prometheus collects metrics from services.

This only applies to the load testing setup described in Keylcoak Benchmark, see the Metrics section in the Observability Guide.

About Prometheus

Prometheus collects metrics from services and the Kubernetes platform and provides them to Grafana.

Visit the Prometheus website for more information.

Opening Prometheus

Prometheus is deployed by default.

Assuming the command minikube ip returned 192.168.39.39, the console is available on http://prometheus.192.168.39.39.nip.io.

minikube’s IP address changes every time the minikube instance is re-created.
prometheus

Running custom queries

Enter an expression in search field and press Execute to run the query. Auto-completion is available. See the PromQL docs on how to run queries.

Example 1. Show all metrics retrieved from Keycloak

{job='keycloak/keycloak-metrics'}

Example 2. Show used bytes for different JVM memory pools

jvm_memory_used_bytes{job='keycloak/keycloak-metrics'}

To show a minimal graph, switch to the Graph tab.

While this is good for ad hoc queries, use Grafana for advanced dashboards which can be persisted.

Diagnostics

Open the menu Status  Configuration to see the configuration which is auto-generated from the different custom resources created for Prometheus in Kubernetes.

Open the menu Status  Targets to see if Prometheus can connect to all targets to collect the metrics.